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Discussion Starter · #1 ·
Finally got all of the suspension upgrades/refresh finished 2 weeks ago. My 6–8-week project (in my head at least) turned into 4 months of work. To be fair, I don’t think I ever worked on it for more that 3-4 hrs at time. If you like your free time to work on your cars, don’t have kids I guess. It is a 2009 GT with 77,000 miles that has been daily driven in Ohio winters for the last 8 years. Ok, on to the parts installed list:
Front end:
DBA rotors slotted-T3 4000 series
Carbotech brake pads-1521 street compound
King Springs-SL front 0.9” drop front
Pedders GSR struts-9464
Superpro front strut mount- Polyelast SPF-1590AK
Mevotech supreme lower control arm-one with greaseable ball joint
Pedders radius rod bushing-into stock arm-EP6753
GM rubber spring seat-front-old one was rotting away
Pedders steering rack bushing-EP2112
Pedders front bump stops-4358

Rear End:
DBA rotors slotted-T3 4000 series
Carbotech brake pads-1521 street compound
King Springs-SL rear 1” drop
Pedders GSR rear shocks-9295
Superpro rear spring seat
Rear upper shock mount plates with bushing-GM Camaro part #92213101 and 92233769
BMR Lower control arm-non-adjustable TCA028
BMR toe rods-adjustable poly TR003
BMR trailing arms-non-adjustable poly-TCA026
Rear upper control arm bushing-Pedders EP7263-(metal jacket, not like pic on website!)
Subframe/Cradle bushing inserts-Pedders EP1169
Differential bushing-Pedders EP1167 (street version with voids)
SPC alignment bolt kits- 87430 (lower control arm inner camber and Toe rod inner bolt)
Whiteline toe lock washers-W63175 (locks in camber bolt for use with BMR adjustable arm)
Various new GM bolt/nuts where the old had a lot of rust

While I was at it, drained and refilled diff oil, also bleed the brake fluid. Hardest part of the job was rusted/froze lower rear control arm inner bolts. I had to cut these out with a hackzall and about a dozen blades for both sides. That was probably 2 hrs of cutting and 8 battery recharges per side. No good way to get those out when they are rust welded to the inner metal sleeve of the stock bushing.
2nd worst was the differential bushings. I tried the threaded rod/washer method with the ball joint kit receiving sleeve to try and press them out, but I couldn’t get it to work. I could not get enough of the metal sleeve bent in so the washer could push them out evenly. I took a 2” hole saw to cut out the rubber part of the bushing and carefully pounded/pried out the sleeve with a large screwdriver.

Ok, the fun part, after a 3.5 hr alignment at the local shop (trouble getting rear camber to what I wanted), got to drive it. First impression was it was not as stiff/harsh as I expected. For perspective, I have a 2005 GTO that has all Pedders poly bushing/spring/shocks. For me, the GTO is on the edge of being too harsh of a ride for a daily driver on bad roads. But, that was fine for me as it is a second car for fun I drive only in the summer. I wanted my DD G8 to be somewhere in between ride of the GTO, and the ride of a stock G8. My stock G8 when I got it with 15,000 miles was always too floaty on the bumps. Now, it is just about where I wanted it to be ride wise. The combination of the Pedders struts with the King springs makes for a very nice ride to me.

What I would do differently: Probably drop the front end another 0.25 or 0.5” or so with the King SSL springs or Superpro elastomer upper bushing. The front end tire/fender gap is slightly more than what it is in the rear, and it bugs me a little. I think the elastomer superpro bushing drops it another 3/8” or so, and that would be about perfect. Also, I want to add the BMR sway bars, as the car still has a lot of lean in the hard corners. That might wait until next summer. Other than that, I am very happy with the upgrades, just not with how long it took me.
 

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Is the rear end noticeably lower than the front? Are you writing this a same day as finishing the job or have the springs settled to where they should be? Also sounds like you could have made life alot easier with an air hammer and/or a cutoff wheel. Battery power is cool but there are still a few tools that are still better with air. Also a good ol fashioned sawzall that plugs in is super useful in some applications.

I would assume the G8 would do better with a stiffer suspension due the the weight difference compared to a GTO. Glad to hear everything worked out 👍
 

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Discussion Starter · #3 ·
Ride height from center of wheel to fender in the front was 371mm, in the rear was 370. I only measured passenger side. Everything has been done for about 2 weeks, so it could settle some more I guess. I had already spent too much on tools for this, didn't want to spend any more for air tools. Had 2 batteries for the saw, so by the time one was dead, the other was charged up. Or, it gave me a 5 min break to get the feeling back in my hands.
 

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RANDOM VICTIM S.O.B.
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Finally got all of the suspension upgrades/refresh finished 2 weeks ago. My 6–8-week project (in my head at least) turned into 4 months of work. To be fair, I don’t think I ever worked on it for more that 3-4 hrs at time. If you like your free time to work on your cars, don’t have kids I guess. It is a 2009 GT with 77,000 miles that has been daily driven in Ohio winters for the last 8 years. Ok, on to the parts installed list:
Front end:
DBA rotors slotted-T3 4000 series
Carbotech brake pads-1521 street compound
King Springs-SL front 0.9” drop front
Pedders GSR struts-9464
Superpro front strut mount- Polyelast SPF-1590AK
Mevotech supreme lower control arm-one with greaseable ball joint
Pedders radius rod bushing-into stock arm-EP6753
GM rubber spring seat-front-old one was rotting away
Pedders steering rack bushing-EP2112
Pedders front bump stops-4358

Rear End:
DBA rotors slotted-T3 4000 series
Carbotech brake pads-1521 street compound
King Springs-SL rear 1” drop
Pedders GSR rear shocks-9295
Superpro rear spring seat
Rear upper shock mount plates with bushing-GM Camaro part #92213101 and 92233769
BMR Lower control arm-non-adjustable TCA028
BMR toe rods-adjustable poly TR003
BMR trailing arms-non-adjustable poly-TCA026
Rear upper control arm bushing-Pedders EP7263-(metal jacket, not like pic on website!)
Subframe/Cradle bushing inserts-Pedders EP1169
Differential bushing-Pedders EP1167 (street version with voids)
SPC alignment bolt kits- 87430 (lower control arm inner camber and Toe rod inner bolt)
Whiteline toe lock washers-W63175 (locks in camber bolt for use with BMR adjustable arm)
Various new GM bolt/nuts where the old had a lot of rust

While I was at it, drained and refilled diff oil, also bleed the brake fluid. Hardest part of the job was rusted/froze lower rear control arm inner bolts. I had to cut these out with a hackzall and about a dozen blades for both sides. That was probably 2 hrs of cutting and 8 battery recharges per side. No good way to get those out when they are rust welded to the inner metal sleeve of the stock bushing.
2nd worst was the differential bushings. I tried the threaded rod/washer method with the ball joint kit receiving sleeve to try and press them out, but I couldn’t get it to work. I could not get enough of the metal sleeve bent in so the washer could push them out evenly. I took a 2” hole saw to cut out the rubber part of the bushing and carefully pounded/pried out the sleeve with a large screwdriver.

Ok, the fun part, after a 3.5 hr alignment at the local shop (trouble getting rear camber to what I wanted), got to drive it. First impression was it was not as stiff/harsh as I expected. For perspective, I have a 2005 GTO that has all Pedders poly bushing/spring/shocks. For me, the GTO is on the edge of being too harsh of a ride for a daily driver on bad roads. But, that was fine for me as it is a second car for fun I drive only in the summer. I wanted my DD G8 to be somewhere in between ride of the GTO, and the ride of a stock G8. My stock G8 when I got it with 15,000 miles was always too floaty on the bumps. Now, it is just about where I wanted it to be ride wise. The combination of the Pedders struts with the King springs makes for a very nice ride to me.

What I would do differently: Probably drop the front end another 0.25 or 0.5” or so with the King SSL springs or Superpro elastomer upper bushing. The front end tire/fender gap is slightly more than what it is in the rear, and it bugs me a little. I think the elastomer superpro bushing drops it another 3/8” or so, and that would be about perfect. Also, I want to add the BMR sway bars, as the car still has a lot of lean in the hard corners. That might wait until next summer. Other than that, I am very happy with the upgrades, just not with how long it took me.
What settings did you spec for the alignment if you don't mind me asking?
I have tried two different shops local to me and I just do not like the feel. It feels darty over bumps and light/wondering in the front at upper HWY speeds. It just does not feel planted and gives me no confidence in control.
 

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What settings did you spec for the alignment if you don't mind me asking?
I have tried two different shops local to me and I just do not like the feel. It feels darty over bumps and light/wondering in the front at upper HWY speeds. It just does not feel planted and gives me no confidence in control.
Sounds like worn control arms.
 

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Discussion Starter · #10 ·
Yeap, that's the one I gave them. It is almost the same as the BMR recommendations. The front end was fine, I didn't use the caster washers in the front. I had read that those make it a little bit harder maneuvering at slow speeds like parking lots, so didn't want that since this is a DD. So, caster is close to stock, and no way to adjust that here.

They could not get the rear camber close to what i wanted. Not sure what the problem was, might be because I am lowered in the back and need an adjustable lower control arm? The technician said he would have to drill out the bolt holes if I wanted it closer to the -1.0 rear camber spec.

Automotive tire Font Line Motor vehicle Tire
 

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RANDOM VICTIM S.O.B.
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131 Posts
Yeap, that's the one I gave them. It is almost the same as the BMR recommendations. The front end was fine, I didn't use the caster washers in the front. I had read that those make it a little bit harder maneuvering at slow speeds like parking lots, so didn't want that since this is a DD. So, caster is close to stock, and no way to adjust that here.

They could not get the rear camber close to what i wanted. Not sure what the problem was, might be because I am lowered in the back and need an adjustable lower control arm? The technician said he would have to drill out the bolt holes if I wanted it closer to the -1.0 rear camber spec.

View attachment 185979
Wretched Motorsports pdf file
Good stuff guys, Thanks a lot!
 

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I had replaced both LCA's and both struts, I do not have much confidence in the shops I used.
Which struts, strut mounts and lower control arms were used? Why the lack of confidence?
 

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RANDOM VICTIM S.O.B.
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131 Posts
Struts were OEM FE2, LCA's were mevotech, the mounts were KYB.
It started after the first alignment, which was done for faulty LCA's. The car was great before that, even with worn parts.
After the first alignment the rear would almost step-out going over bumps, the front felt OK, but over all I did not have confidence in late corner braking and the over all twitchyness of the car in the wet was very sketchy.
The second alignment settled the rear end from its wanting to step-out, but brought the front end wanting to dart to either side over bumps and in the wet, also a light wandering at higher speeds. Just the general feeling of the car not being planted is what I am getting from it, straight line, and corner braking feel squishy through the steering wheel, if you know what I mean? Overall in the wet it just feels like it could decide to go wherever it wants if it chooses too. lol
 

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Discussion Starter · #15 ·
You could also try BMR specs:

Font Screenshot Rectangle Number Parallel


The wandering front end is what I was feeling for sure before doing all of the this. Along with the car getting seriously disrupted going over moderate to large bumps. Also, the rear end stepping out on hard cornering was there also. I think the springs/struts in the front along with the alignment fixed the wondering, and the cradle inserts bushings in the rear fixed the stepping out feeling for me.
 

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RANDOM VICTIM S.O.B.
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Awesome to hear! Thanks for your input, it makes me feel like I can get this back to normal.
I am planning to do many of the upgrades you have, during the winter storage.
 
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